Somatosensory Receptor(s): a cell or group of cells specialized to detect changes in the environment and trigger impulses in the sensory nervous system. (OxfordMed) Specialized to respond to a particular physical property, such as "touch,"  "light," or "temperature." (Kandel, 447)

Translate different kinds of information from the external world into electrical patterns that are sent down our neurons. (Doidge, 18) Rapidly adapting somatosensory receptors are specialized to tell us when a “stimulus” occurs. "Meissner's corpuscles," "Pacinian corpuscles," and "Ruffini corpuscles" are all rapidly adapting receptors. Slowly adapting somatosensory receptors detect whether a “stimulus” is still occurring. These receptors continue to respond as long as a sensory event is present. (Kolb, 371) Also referred to as a ‘receptor cells,’  ‘sense receptors,’ and 'somatic receptors.'

Exteroceptor(s): specialized to detect sensory information from the external environment (such as "visual,"  "olfactory,"  "gustatory,"  "auditory," and tactile stimuli). Located close to the body surface. Sensitive to touch (light stimulation of the skin surface), "pressure" (in the deep layers of the skin, or deeper parts of the body), temperature, "pain," and "vibration." (Patestas, 139)

Interoceptor(s): detect sensory information concerning the status of the body’s internal environment, such as stretch, "blood pressure,"  "pH," "oxygen" or "carbon dioxide" concentration, and “osmolarity.” (Patestas, 139)

Osmoreceptor(s): a group of cells in the “hypothalamus” that monitor "blood" concentration. Should this increase abnormally, as in "dehydration," the osmoreceptors send nerve impulses to the "hypothalamus," which then increases the rate of release of "vasopressin" from the "pituitary gland." Loss of water from the body in the urine is thus restricted until the blood concentration returns to normal. (OxfordMed)

Nociceptor(s): a receptor that responds to the stimuli responsible for the sensation of pain. (OxfordMed) Detects piercing pain, heat pain, chemical pain, "joint" pain, deep tissue pain, tickle, and itch. (Blakeslee, 8) Found in the skin, “muscles,” and internal "organs." (Hockenbury, 102) Rapidly adapting receptors that are sensitive to noxious or painful stimuli. Located at the terminations of lightly "myelinated" "free nerve endings" or unmyelinated fibers. (Patestas, 139)

A-Delta Fibers: represent the ‘fast pain’ system. Transmit the sharp, intense, but short-lived pain of the immediate injury. (Hockenbury, 103)

C Fibers: unmyelinated fibers transmitting pain. (Patestas, 139) Represent the ‘slow pain’ system. As the sharp pain subsides, C fibers transmit the longer-lasting throbbing, burning pain of the injury. The throbbing pain carried by the C fibers gradually diminishes as a wound heals over a period of days or weeks. (Hockenbury, 103)

Mechanoreceptor(s): activated following physical ‘deformation’ due to touch, pressure, stretch, or vibration of the skin, muscles, "tendons," "ligaments," and (joints) in which they reside. (Patestas, 139) Cells specialized to (transmit) mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the “inner ear” hair cells, which mediate hearing and balance. (MeSH)

Free Nerve Endings: present in the epidermis, dermis, cornea, dental pulp, "mucous"  "membranes" of the oral and "nasal cavities" and the "respiratory," gastrointestinal, and urinary tracts, muscles, tendons, ligaments, joint capsules, and "bones." They are stimulated by touch, pressure, thermal, or painful stimuli. (Patestas, 140)

Haptic Receptor(s): consists of a "dendrite" attached to a hair or to connective tissue or a dendrite encased in a capsule of tissue. Mechanical stimulation of the hair, tissue, or capsule activates special "channels" on the dendrite, which in turn initiate an "action potential." (Kolb, 370)

Meissner’s Corpuscles: respond to touch. (Kolb, 371) Present in the skin of the lips, forearm, palm, and sole, as well as in the connective tissue of the tongue. They are "rapidly adapting" and are sensitive to (fine) tactile discrimination, and are thus of great importance of the visually impaired by permitting them to be able to read "Braille." (Patestas, 141)

Pacinian Corpuscles: respond to fluttering sensations. (Kolb, 371) Important sensory receptors involved with the sense of touch, located beneath the skin. When stimulated by pressure, it converts the stimulation into a neural message that is relayed to the brain. (Hockenbury, 102)

Ruffini Corpuscles: respond to vibration. (Kolb, 371)

Proprioceptor(s): sensitive to the stretch of muscles and tendons and the movement of joints. (Kolb, 371) Located in the muscles and joints. Provide information about body position and movement. Constantly communicate information to the brain about changes in body position and muscle tension. (Hockenbury 104-105) Transmit sensory information from muscles, tendons, and joints about the position of a body part, such as a limb in space. There is a static 'position sense’ relating to a stationary position and a ‘kinesthetic sense’ relating to the movement of a body part. Includes the receptors of the “vestibular system” located in the inner ear, relaying sensory information about the movement and orientation of the head. (Patestas, 139) There are two kinds of proprioceptor cells – one is embedded in your muscles and tendons and measures stretch. The other is embedded in the cartilage between your skeletal joints and keeps track of load (weight) and (the) rate of slippage in each joint. Our brain uses these inputs to calculate limb speed and direction (Blakeslee, 9)

Thermoreceptor(s): sensitive to warmth, cold, excessive heat, or excessive cold. (Patestas, 139) Cellular receptors which mediate the sense of temperature. Thermoreceptors in vertebrates are mostly located under the skin. In mammals there are separate types of thermoreceptors for cold and for warmth and “nociceptors” which detect cold or heat extreme enough to cause pain. (MeSH)